Pneumatically supported structure

ABSTRACT

A pneumatically supported structure of polyhedral configuration has a plurality of diagonal anchors running between foundation members at the corners of the structure and lying along diagonals thereof. In addition, rigid arches span the foundation members along at least some of the sides and act as supporting members for the flexible skin which is used in sections between the anchors. A double-wall structure may be provided in which the air enters the space between the inner and outer skin and passes out of the space at the base of the structure.

O United States Patent 1 1 1 5 Linecker Aug. 14, 1973 [54] PNEUMATICALLYSUPPORTED 2,797,696 7/1957 Fritsche 135/1 R STRUCTURE FOREIGN PATENTS ORAPPLICATIONS [76] Inventor: Josef Linecker, A 5230 Mattighofen, 311,43711/1955 Switzerland 135/1 R Austria 992,086 10/1951 France 52/2 655,4454/1929 France 52/2 [22] Filed: Apr. 2, 1971 OTHER PUBLICATIONS [21]Appl' l30758 House and Home, p. 133, 134, Sept. 1956, Eliot Noyes.

[52] us. CI. 52/2, 52/80, 52/88, P im y Ex min r-Frank L- Abbott 135/ 1R Assistant Examiner-Leslie A. Braun 51 Int. Cl E04b 1/34 ArwmeyKarl ERoss [58] Field of Search 52/1, 2, 80, 86,

52/88; 135/1 R [57] ABSTRACT! A pneumatically supported structure ofpolyhedral [56] Referenm Cited configuration has a plurality of diagonalanchors run- UNITED STATES PATENTS ning between foundation members atthe corners of the 1 818 54s 8/1931 Eriksson 52 2 strucmre and lyingalng diagmals 2:782:794 2 1957 White 52/2 rigid arches p the foundationmfimbers along at least 2,823,683 2/1953 South at 135/ R some of thesides and act as supporting members for 1,827,486 10/1931 Paulsen...52/2 the flexible skin which is used in sections between the 2,297,1501942 anchors. A double-wall structure may be provided in 2,895,4907/1959 Dimond 52/ which the air, enters the space between the inner and2,41 16 1 1/1946 CaP'ta 52,2 outer skin and passes out of the space atthe base of the 3,256,895 6/1966 Duquette 52/2 structure R27,232 11/1971McLorg 52/2 3,059,655 10/1962 Bird 52/2 17 Claims, 22 Drawing FiguresPatented Aug. 14, 1973 3,751,862

5 Sheets-Sheet 1 Patented Au g; i4, 1973 5 Sheets-Sheet 2 Patented Aug.14, 1973 3,751,862

5 Sheets-Sheet 5 Patented Aug. 14, 1973 3,751,862

5 Sheets-Sheet 4 Patented Aug. 14, 1973 3,751,862

5 Sheets-Sheet 5 FIE-2.75

1 PNEUMATICALLY SUPPORTED STRUCTURE FIELD OF THE INVENTION My presentinvention relates to pneumatically supported structures and, moreparticularly, to improvements in structures designed to enclose largeareas, e.-g. lecture and meeting halls, auditoriums exposition anddisplay stadia, performance theaters, bathing and swimmingestablishments, and any space-which is to be environmentally controlledor isolated in whole or in part from the atmosphere, wherein at leastpart of the structural support for the walls is provided by air at apressure greater than ambient.

BACKGROUND OF THE INVENTION Pneumatically supported structures for thepurposes described have gained increasing importance because of therelatively small amount of labor required to erect a large enclosure,because of the fact that the labor involved in such erection need not behighly skilled or highly paid, because minimum previous preparation ofthe building site is required, and because the cost of materials for thestructure is substantially smaller than for rigid-wall prefabricated orcustom-built structures.

However, these pneumatically supported structures, which are held up bythe introduction of air at a pressure at least slightly above ambient,have some significant disadvantages as they have been constructedheretofore. For example, air loss is a problem which can be countered inconventional systems only by sealing the walls thereof substantiallycontinuously to a foundation or base. This, in turn, increases the costof preparing the site and may not be technically or estheticallydesirable. In some cases, even the shape of the structure is determinedby the need to seal the skin to the foundation and ground level anddetracts from the usable space within the structure and the appearancethereof from without. The foundation anchorage of the skin continuouslyalong the sides of the structure also re duces the versatility of theenclosure since the shapes in which the enclosure can be provided arelimited. Finally, I may note that it is known to provide reinforcementwires or anchors in flexible-wall pneumatically supported structures,generally only at entrance points or in double-hall constructions in theinterior, but these anchoring methods have also proved to beunsatisfactory for many purposes. In practical respects, therefore, itcan be said that the use of flexible-wall pneumatically supportedstructures has been severely hampered by prior-art methods of securingthe strucutre to the foundation and/or of providing anchoring orreinforcing elements for the walls or roof of the structure.

OBJECTS OF THE INVENTION It is, therefore, the principal object of thepresent invention to provide an improved pneumatic construction orair-supported structure, especially for large areas, whereby theaforedescribed disadvantages are ob viated.

It is another object of the invention to provide, in a pneumaticallysupported enclosure, improved means for sealing th junction of theflexible skin with the foundation or support members.

A further object of my invention is to provide an improved system ofanchoring the flexible skin of an airsupported structure to a foundationwhereby the need for continuous sealing of the skin to the foundation atground level can be avoided.

Still another object of my invention ls the provision of an improvedsupport structure for a pneumatic enclosure which requires only pointsupport or connection to the foundation.

SUMMARY OF THE INVENTION These objects and others which will becomeapparent hereinafter are attained, in accordance with the invention,with a pneumatically supported structure for single enclosure (singlehall) or double enclosure (double hall) or any arrangement of the wallsof the enclosure which is generally polyhedral, wherein foundationmembers are provided along at least the exterior of the structure ofcorners thereof (vertices of the polygonal plan) while anchoringelements run from these foundation members along diagonals of the planand cross or are in contact at a crossing point of the diagonals, theflexible skin being provided in sections between these reinforcingelements. Between the foundation members, moreover, along the peripheryof the structure, I provide arch-shaped rigid supports adapted to formwindow or wall elements to which the flexible skin is secured so that,when the skin is stretched by superatmospheric pressure, no stress isapplied to the arches, while the arches carry only the weight (at most)of the flexible skin when the interior of the enclosure is deflated.Consequently, in the presence of internal pressure, the anchor elementsextending along the diagonal of the structure, take up any outwardstress which is transformed into tension on these elements and upon thefoundation. No stress, or substantially no stress, is applied to thearch members in the expanded condition of the structure. However, whenthe pressure within the enclosure falls below ambient, the arches atmost take up only the weight of the skin so that the skin hangs fromthese arches.

The tensioning of the system is preferably so arranged that the skincannot fall to the floor, even in a condition in which the internalpressure falls to ambient. This may be guaranteed by erecting the archesso that the distance D across which the skin is stretched s2 H +(L/4where H is the height of the arch and L is the horizontal distancebetween the arches across which the length D of flexible skin isstretched.

The arches can span the sides of the enclosure from foundation tofoundation openly and, because they need not carry any load but theirown mass and the weight of the skin in an unstretched state, can extendacross long spans. However, even these forces can be taken up in wholeor in part by vertical struts or supports spaced along the side andextending between the foundation and the arch. It has been found tobeadvantageous, with large spans, to provide the diagonally extendinganchors as metal bands or strips or some similar material and to providenetworks of such bands between which the fabric or skin can bestretched. In general, the fabric or skin is stretched between pairs ofsuch bands.

According to another feature of the invention, the anchor elements arecarried in part, preferably at their crossing points, by extensibleremovable masts which are extended and placed in position upon erectionof the enclosure. The skin is releasably or loosely connected to thesupports or arches and may be provided with means enabling the skin tobe displaced longitudinally relative to the diagonal elements viasliding shoes, loop arrangements or the like. An air-tight connectioncan be provided advantageously by a U-section, each bead engageable withthe arches and supports, an inflatable tube adapted to be lodged in agroove or a like conventional sealing junction. The connection of theskin with the elongated anchor elements can be effected by loops, shoes,groove arrangements or the like. To erect the structure, the flexibleseal or skin is removed from the supports or arches and from the floorand is shifted along the diagonal anchors to the mast which previouslyhas been elongated to raise the anchor elements and stretch the fabric.

It has also been found that pneumatically supported structures which areused to enclose a space at a materially different temperature from thatof the ambient atmosphere, require the solution of special problems. Theatmospheric temperature may, of course, be higher or lower than that inthe interior of the enclosure, especially when the latter is employed tohouse a swimming pool, curative bath or other body of water. Showerhouses and like installations equally are faced with this problem. Theadditional difficulties arise from the fact that such enclosures havehigh interior humidity and temperature. When the temperature outside theenclosure is relatively low, the inner surface of a singlewallconstruction may have a temperature above the dew-point of the interiorand condensate may form along this surface. This is especiallypronounced when the enclosure houses heated baths and the drawback couldnot be avoided with conventional air-supply systems. According to thepresent invention, however, an enclosure faced with this problem isprovided with a double-wall construction or with two flexible shells,between which a compartment is created. Advantageously, the skin of thestructure is formed from tubular stretches such that individualcompartments are provided between the flexible sheets of each strip andthe compartments of adjacent strips are separated from one another attheir seams. In this'case, I provide inlets and outlets spaced atopposite ends of the elongated compartments for the circulation of airthrough them. For example, inlet compartments may be provided close tothe top of the structure when the strips run upwardly and downwardly,while an outlet is provided close to the base of the compartment fromwhich depleted air is withdrawn. Since the air circulated through thecompartment has the same temperature and humidity of the air within theenclosure, the inner face of the double-wall covering does not sustaincondensation. The outlets of the compartments, at least along one wallof the structure, may open collectively into a channel formed in thefoundation and connected to the aircirculating system. With moderatetemperature and humidity differentials between the ambient atmosphereand the interior of the enclosure, recirculation of all or a major partof the air conducted through the compartments is no problem. However,when high-temperature differentials exist across the coverage of theenclosure, I prefer to return only a fraction of the air traversing thecompartments to the interior. The balance of the air supplied to theinterior of the enclosure may be dry fresh air so that the humiditygenerated by the pool, showers etc. is reduced.

In hangar-type bathing installations, the cost of elimi nating moistureby disposal of the air generally amounts to about 60 percent of thetotal heating cost. I have found it to be desirable and advantageous tosimplify the venting of moist air into the atmosphere by providing atthe top of the structure one or more venting valves communicatingbetween the interior and the atmosphere. In this case, a valve may beprovided at the mouth of each flow compartment communicating with theinterior so that the valve selectively is operated to vent air from theinterior of the structure to the atmosphere or to direct the air alongthe flow compartments.

It should be noted also that the passage of warm air through the flowcompartments also insulates the interior of the structure and reducessubstantially the operating cost. The savings produced in this mannerare most significant for large hangar-type baths with high air-dischargerates. Thermal calculations have shown that with exterior temperaturesof about 5C, the heating of the pool suffices to provide the necessarytemperature in the interior of the enclosure so that no additionalenergy for room heating is required.

During the passage of the discharged air through the flow compartments,the air is cooled and moisture condenses along the outer surface of thecovering and can be conducted away by gutters or the like. The outerskin thus acts as a condenser and the outflowing air is dried. Thelatter air can be totally or partly returned to the heating installationand thereafter to the chamber, if desired, or simply recirculated to theinterior of the enclosure.

Even in summer, when the structure is exposed to strong solar radiation,the system of the present invention has significant advantages. Thedischarged air carries away part of the heat developed in the flowcompartments and acts as an insulating medium. It has been found to beadvantageous to provide the outer surface of the inner wall of areflecting material, i.e. to metallize this inner wall. Here, too,pneumatic valves are preferably disposed between the inner and outerwalls for fluid-pressure operation to permit the inner wall to collapseonto the outer wall and thereby reduce the insulating effect when partof the solar radiation is to be salvaged for room heating. When a numberof valves are provided, or when a valve is inserted for each flowcompartment, it is possible to operate the shady side of the enclosurewith maximum insulating effect and to reduce the insulating effect atthe sunny side to obtain more efficient heating.

it has also been found to be advantageous, in view of the fact thatdifficulties are encountered in affixing the inner layer to the outerlayer of the covering and in joining the adjacent inner layers ofrespective strips, to provide a bead-forming profile on the outer layerand a fastening member extending along and receiving this profile. Thefastening member may have an additional pair of grooves to receive beadsof a pair of laterally adjoining inner layers or webs of the covering aswell as a further groove between the latter two grooves, to receive thebead of a covering strip adapted to mask the junction of the fabricstrips forming the inner layer of the covering. A hollow of the profileor junction member may also be used as a duct for the recirculated'orvented air, as part of the venting valve system mentoned earlier and/oras a service duct through which, for example, electrical conductors maybe led.

According to another feature of the invention, the structure consists ofat least one window fitted into a wall and preferably conforming incurvature to that of the wall. The window element may be composed offrame members, e.g. profiles, adapted to receive beads of the coveringto seal the latter and even provide a seal for both an inner and outerlayer of the covering. Preferably, this window element comprises a framewhich is spanned by a single translucent sheet or two spacedaparttranslucentsheets forming an insulating space, the frame having ahorizontal pedestal above the outline of which the center of gravity ofthe window is located. This pedestal may be a plate adapted to bereceived upon a foundation or to form part of the foundation, butpreferably includes means forming a duct for supplying air to theinter-wall space of the covering, removing air from this inter-wallspace, delivering air to or removing it from the interior of thestructure proper, collecting and conducting away moisture, etc. Theorientation of the window such that its center of gravity lies withinthe outline of the pedestal and, preferably, within the pedestal,permits the window structure to be set upon the ground or the foundationfor rapid and convenient positioning and renders the same freestandingwhile excluding loading of the fabric structure. Advantageously, theframe of the window converges upwardly so that the window may be builtin between a pair of upwardly convergent anchors. The outer form of thewindow corresponds to the surface defined by the generatrices spanningthe anchor elements between which the window is built. It will beapparent that this construction allows the window to be inserted withoutdifficulty and permits minimum dimensioning of the window.

Since it has been found to be difficult and expensive to produce windowstructures of this type from preformed profiles, [prefer to cast thewindow elements (i.e. the frame) from materials such as concrete andsynthetic resin. Instead of metal forms for such casting, however, ithas been found to be advantageous to provide bendable forms, e.g. out ofa fiberglass/epoxy material, which can be deformed in a supportingstructure to correspond to any desired curvature of the wall. By simplymodifying the supported structure, a mold of this type can be used forsubstantially any curvature. The supporting structure is advantageouslymade from wood.

In summary, the invention comprises basically a pneumatically supportedstructure with a foundation having anchor points at least at the cornersof the polyhedral structure, a flexible skin or covering, e.g. of arubberized fabric, enclosing the space within the foundation, and aplurality of anchor elements of wire or band configuration spanningdiagonally opposite anchor points of the foundation and overlying thecovering to retain the latter against outward movement, the anchorelements having a junction point at the intersection of the diagonals,either by virtue of an actual crossover of the elements or by virtue ofa simple contact at this intersection point. At least one wall of thestructure may be formed by uprights or posts, mounted upon respectivefoundation members and having free upper ends to which the covering isanchored, or which are held by the covering under some compression.Between the uprights, strips of the covering material are preferablystretched.

A highly important feature of the invention resides in the provision ofsupporting arches in at least one wall, the arch either spanning theentire wall between the foundation points defining same, or beingsubdivided into a number of arches which collectively span the wall. Inaddition, upright members may be provided at spaced locations along thewall for additional support. Important to the present invention is thefact that the inflated structure applies outward stress upon the anchorelements and not significantly upon these arches, so that the coveringmay be affixed to the latter in a sealing manner but without theforce-transmission requirements which might otherwise be expected. Thearches need be expected only to support their own weight and the weightof the covering in a deflated state of the structure.

DESCRIPTION OF THE DRAWING The above and other objects features andadvantages of the present invention will become more readily apparentfrom the following description, reference being made to the accompanyingdrawing in which;

FIG. 1 is a diagrammatic vertical cross-section of a double-wallstructure according to the present invention:

FIG. 1a is'a perspective view of another similar structure; FIG. 1b is adetail of a modification;

FIG. 2 is a plan view of the arrangement of FIG. 1;

FIG. 3 is a diagram representing a plan view of a polyhedral structure,according to the invention, which has sides inclined to therectangularly adjoining sides;

FIG. 4 is a vertical cross-section through a gassupported structure inwhich a secondary support is provided for the flexible skin;

FIGS. 5 7 are detail views in cross-section through the anchoringelements, for example, along the line V V in FIG. 2 showing theconnection to the diagonally running anchor elements to the flexibleskin;

FIG. 8 is a cross-section through a portion of an arch member accordingto the present invention, e.g. along the line VIII VIII of FIG. 2, drawnto an enlarged scale;

FIG. 9 is a side-elevational view of an open enclosure with removablesupport mast;

FIG. 9a is a plan view of the latter enclosure;

FIG. 10 is a vertical cross-section of the left-hand side of ahemispherical air-supported double-wall enclosure;

FIG. 11 is a view similar to FIG. 10 showing the double-wall structurein a somewhat collapsed state;

FIG.,12 is a partial plan view of the venting valve of this structure;

FIG. 13 is a cross-section taken generally along the line XIII XIII ofFIG. 12 and showing the venting valve in a closed condition wherein,however, the valve between the interior of the enclosure and thedoublewall chamber is open;

FIG. 14 is a detail cross-sectional view, drawn to an enlarged scale,showing the connection of the inner and outer shells via a connectingprofile;

FIG. 15 is a vertical section through a window element for use in apneumatically supported structure according to the invention;

FIG. 16 is an elevational view thereof;

FIG. 17 is a cross-section through the profile members forming thewindow element;

FIG. 18 is a plan view of a door element having a rotatable door mountedin a framelike structure; and

FIG. 19 is a side-elevational view, in cross-section, of a spacerinterposable between the inner and outer shells or skins.

SPECIFIC DESCRIPTION Referring first to FIG. 1a in which a rectangularenclosure, eg a bathing or swimming enclosure of square plane, isrepresented in diagrammatic perspective view, it can be seen, that thebasic elements of the pneumatically supported structure 200 includefoundation at the corners or vertices 201, 202, 203 and 204 of eachrectangular unit. In FIGS. 1 and 2, the locations of the foundations andthe structure thereof are shown in greater detail. For the purposes ofFIG. 1a, however, it will suffice to observe that each of thefoundations consists merely of a footing and a post rising from thefooting to grade level. Along the wall 205, moreover, there are providedindividual footing for each of a plurality of vertical posts 206 whichare vertically spaced along this side of the structure and reachupwardly to support a concrete arch 207 (FIG. 8) when the arch isintended to span especially large distances between the foundations 201and 202. The space between each pair of posts 206 may be closed by astrip of the flexible skin (e.g. rubberized fabric) forming the walls ofthe enclosure.

A pair of diagonally extending anchoring elements 208 and 209,respectively bridging foundation posts 202 and 204 and foundation posts201, 203, intersect and are joined at the contact point 210 in a mannersimilar to that represented at 20 in FIG. 2. It should be understood, ofcourse, that the diagonally extending elements need not cross as shownin FIG. 1a, but may merely be connected at the diagonal intersectionpoint as shown at 211 in FIG. lb.

The members 208 and 209 may have the configurations illustrated in FIGS.5 7 and may be connected to the skin in a similar manner. The members208 and 209 are bridged by rubberized fabric strips 212, which may beseamed at 213 in the usual manner, to provide a fluid-tightroof-and-wall structure for the enclosure. Along the rim 214 of the arch207, however, the skin, represented generally at 215, is clamped,preferably with a corrugated sealing arrangement as shown in FIG. 8.

It is important to note that the connection does not apply significantstress to the arch 207 which need merely take up the weight of the skinwhen the pressure within the enclosure falls. In the embodimentillustrated in FIG. 1a moreover, the wall 205 is shown to be open. Morecommonly, door and window structures may be provided (FIGS. 18) or thewall will simply be closed and a conventional door or other openingarrangement provided for access to the interior of the enclosure.Another wall 216 of the enclosure may be formed by an arch 217 which isanchored at the foundation points 201, 202 but is inclined outwardly tothe vertical by contrast with the arch 207 which lies in a verticalplane. The space between the arch and the edge 218 of the skin 215bridging the quadrant defined by wall 216 and anchors 208, 209, is builtby strips of rubberized fabric skin represented at 219. The seam betweenthe roof and the additional strip 219 is also represented at 218 and maybe supported by a further concrete arch if desired. If the concrete arch219 is prestressed, I may provide vertical members 220 under tensionalong generatrices of the substantially cylindrical surface defined bythe arch 217, to place the latter under tension in the verticaldirection. Of course, these vertical members 220 may be used also whenthe arch 217 is not under prestress but merely is subjected to theweight of the fabric skin as the pressure within the enclosure falls.The regions between member 220 are spanned by rubberized fabric strips221.

The rear wall 222 of the enclosure is defined by a rigid arch 223 havingno intermediate supports, but spanning the gap between foundation points203 and 204. As with the other arches already described, the connectionbetween the skin and the arch is accomplished with the systemillustrated in FIG. 8. A rigid antechamber 224 may be provided in anoutwardly bulging rigid structure which also supports the junction 225with the flexible skin. An arch such as that shown at sides 205, 216 or222 may also be provided at this junction, where the antechamber isair-supported as well.

In FIGS. 1 and 2, which illustrate principles of the present inventionin somewhat greater detail, I have shown a two-unit hangar-type bathingenclosure for a swimming pool or like recreational facility or for acurvative pool or spring for medical or therapeutic treatment. Thestructure illustrated in FIGS. 1 and 2 comprises six foundation footings23 at the comers of the squares defining the rectangular plan view ofthe structure. Each pair of diagonally opposite foundation footings 23is spanned by a diagonally extending anchor wire or band (FIGS. 5 7)between which the individual segments or strips of the covering material1 is provided.

The covering material may be applied as described in connection withFIG. 1a and have seams running generally horizontally (FIG. 2). Thesestrips may also be of double-wall construction as will be apparenthereinafter.

The front-side closure of the structure may be provided with supportingarches in an open manner or may be closed with an antechamber 4 bestseen at the lefthand side of FIGS. 1 and 2. Alternatively, a supportingarch may be provided along this side and the antechamber 4 composed of aflexible covering. The flexible covering in all of the embodimentshereafter described preferably consist of rubberized fabric which may bemetallized for radiation reflection as previously discussed.

All or any of the walls may, moreover, be provided with vertical posts 5between the covering 1 and the floor, the posts being resistant tobending and serving as a support for the cover. The covering 1 can, ofcourse, span the gaps between the post 5 as illustrated in FIG. 2 or mayterminate at the tops of the posts so that additional material isprovided in strips between them.

Preferably at least one wall of the structure, generally all of thewalls thereof, is provided with an arch such as that shown at 3 spanningthe rear foundation members 23 (FIG. 4). The arch may be free standing(right rear in FIG. 2) or may be provided with supporting uprights 7(left rear FIG. 2), the covering being sealingly anchored to the arches(FIG. 8). For large spans, it has been found to be economical to providethe vertical supports or studs 7 between the arch and the ground. Inthis case, the arch may even be dimensioned such that it need not carryeven its own weight. In any event, the arches 3 are so constructed andarranged that, upon failure of the internal pressure, the covering hangsfreely between the arches without contacting the ground. Furthermore,this condition permits, as shown in broken lines at the left-hand sideof FIG. 1, the dimensioning of the covering and the anchor elements suchthat inflation of the structure bellies out the covering beyond a planejoining the arches. This is especially desirable for small and mediumspans and does not materially increase the stress applied to the arches.

With large spans, I have found it to be advantageous to provide theindividual covering surfaces 1 with double curvature, i.e. curvature intwo mutually orthogonal planes, whereby the walls of the structure arecurved upwardly to the top or apex of the structure at which thediagonally extending anchor elements are joined.

Furthermore, I may provide one or more arches 3 (extreme right in FIGS.1 and 2), especially for large spans, which are tilted outwardly (i.e.lie in planes inclined to the horizontal) from which vertical elements 8extend downwardly to the ground under tension. The tension elements 8are intended to take up the stress applied to the arch upon failure ofthe pressure within the enclosure. It will be understood that the termarches as here used and illustrated is intended also to include shell ordoor structure to which the fabric covering is connected along an arc.

As shown in FIG. 2, air-inlet openings are provided in the inner layerof the double-wall covering 1 when the structure makes use of flowcompartments between the layers for insulation and air circulation aspreviously described. The air then flows in the direction illustrated byarrows 21 from each horizontally extended flow compartment to openingsat the vertical seams, downwardly to an air duct 22 which is providedalong the foundation. From duct 22, the air is led through air-returnpiping to a heating plant.

In FIG. 3, I show an arrangement in which the structure is not strictlyrectangular. The left-hand side of the structure is a rectangularportion which, at the righthand side is transformed into a parallelogramand eventually terminates in a trapezoid. The structure is generallydescribable as a polygon with foundation points at least at some cornersor vertices of the polygon. In this case, the anchor elements 2 extendalong diagonals so that intersections may be provided at the top of thestructure. However, two or more anchors 2a, for example, may meet ateach connection point. In this case several cross-overs are provided foreach anchor element with anchor elements from a number of otherfoundation points. It follows that the structure according to thepresent invention can be triangular, square or rectangular or,generally, polyhedral. With a single arch-forming outer wall or windowelement according to the invention, various polyhedral structures can bebuilt with unlimitedly increasing size. Furthermore, the polygonalsection may extend at any angle so that extreme versatility inconfigurations is possible. When the arch members are tilted outwardly,moreover, (righthand side in FIG. I) and a number of such elements areprovided, the structure will have a circular configuration.

In FIG. 4, l have shown, in cross section, another structure partlyrepresented in FIG. 2, in which a rigid secondary structure 9 isprovided within the primary structure to support the covering 1 when thelatter relaxes by reduction of the pressure within the enclosure. Inthis case, the arches 3 can have substantially smaller dimensions sincethey need not even take up a significant load of the flexible covering.The internal structure 9 is a lattice work of metal bars with ageodesicdomed configuration or a simple ladder array of bars asrepresented in FIG. 4. The covering bulges outwardly into a smootharcuate configuration upon inflation of the structure, but falls uponthe internal structure 9 and between the bars thereof as shown 'in FIG.4 at 1, when the pressure is reduced or withdrawn. The rigid secondarystructure 9 need be dimensioned only to take up the weight of thecovering and can be of very light construction. It has been found to beadvantageous to provide the rigid structure 9 with hinge joints, atleast along the top of the structure and with feet guided in rails sothat the pneumatic structure can be erected simply by opening out theinternal support 9 and can be closed by folding the latter. Such anarrangement has been found to be desirable in bathing enclosures which,for the summer, may be opened partly to permit direct access of fineweather to the bathing area. In this embodiment, I also show that thefoundation comprises an air-supply duct 25 along the inner edge of theenclosure through which the air is introduced into the interior of theenclosure. The air may pass into the flow compartments as described inconnection with FIGS. 1 and 2 and thence into a collecting duct 24 whichmay register with the interwall compartments of the structure. Thearrangement of ducts 24 and 25 permits control of fluid flow in a simplemanner without mechanical devices for air supply and return.

As previously noted, the skin or covering of the structure of thepresent invention bulges outwardly against the anchor elements 2. I havefound that suitable anchor elements may be formed of pairs of wire asillustrated in FIG. 5. In this construction, two parallel wires 10constitute an anchor element, the wires being interconnected by spacerand profile members 11, preferably of an elastically yieldable material.Member 11 comprises a pair of recesses ll a, lib, extending over morethan 1Y0 ot" the cir cumference of the wires 10 and preferably having adiameter slightly less than that of the wire so that each wire 10 can besnapped into one of the recesses and is held therein by the inherentresiliency of the body. Between the wires 10, the web of member 11 isfonned with a convex portion 1110 which bears upon the covering 1 or maybe connected directly to the latter. Furthermore, I have pointed out theadvantage in some systems, of affording relative movement to the anchorelements and the covering 1, to which end the members 11 may be shoesaffixed to the covering and slidably receiving wires 10 while preventingthem from shifting relative to one another.

In FIG. 6, I have shown another embodiment of the anchor elements whichhere comprises a stack of metal bands or strips H2. The metal bands orstrips, of course, increase the compartment surface between anchoringelement and the covering for improved support against internal pressureand permit the junction points or intersection to be of small overallthickness. The anchorage of the wires 10 and the bands 12 in thefoundation members 23 is effected by screw or bolt junctions. As in thesystem of FIG. 5, the shoe 11d has a curved portion lie in contact withthe covering 1 and a pair of overhanging portions II If and 11g whichretain the bands. FIG. 7 shows an arrangement in which the covering l issecured to the anchor elements so that the individual strips of fabricspan pairs of such anchored elements. More specifically, the stripsoverlap and have loops folded around the beads 13 of respective profileswhich have webs 13 in overlapping relationship. Bolts may be provided asshown at 14 to secure the profiles together which simultaneouslyconstitute the anchor elements (for members 13) while sealinglyconnecting the stretches of the fabric. One or more rubber sealingstrips 140 may, of course, be provided between the overlapping membersto prevent air leakage from the scene.

In FIG. 8, I have shown in cross section the arch-like wall or windowmember which may be provided at 3 as previously described. Aprefabricated channel 15 of substantially U-shaped cross section and ofconcrete is mounted upon the vertical posts 7. The reinforcing rods ofthese posts, or tie members, extend into the channel 15 and are therereceived within a reinforcing basket 26 which is introduced into thechannel after the prefabricated members 7 and 15 have been mounted asshown. Concrete 16 is cast into the channel and the upper surface of theconcrete layer is shaped by an appropriate striker to have alongitudinally corrugated configuration as represented at 17. With theaid of an elastic strip or gasket 18 of similar configuration, a metalband 19 may press the edge of the covering 1 against the gasket 18 andthe concrete support and can seal the structure. Bolts may be anchoredat spaced locations in the concrete for retaining the band 19.

In FIG. 9 and FIG. 90, I have shown another arrangement in which openingand closing of the structure is facilitated. In this embodiment, a mast27, which is longitudinally extensible, is provided at the crossover orintersection point of the anchor elements 2. Furthermore, guy wires 28are provided between the mast and the arch elements 3. Props 29 areprovided to hold the anchor elements 2 away from the arches 3. Foropening the structure, the edge 30', 30", 30" of the covering isreleased from one or more of the arches and the mast 27 raised. Thus theanchor elements and the unopened fabric surfaces remain stretched whilethe covering 1, as shown in broken lines is shoved upwardly to exposethe area therebelow to the exterior.

FIGS. 10 14 show a double-wall arrangement in which the outer supportinglayer 101 of the covering is underlain by an inner foil 102 which isshown to run parallel to the outer layer. The inner shell is sealed tothe foundation to close off the enclosure. Pneumatic valves are providedat the top of the dome 117 of the arrangement at which the air-flowcompartments between the covering layers 10] and 102 terminate. In fact,the dome 117 of the system may be a rigid shaft.

As best seen in FIG. 10, the rigid shell is provided with closed uppervalves blocked by member 118 above the outer covering layer andcommunicating with the atmosphere, and open valves 119 communicatingbetween the interior of the enclosure and the interwall space. At thebase of the enclosure, the interwall space communicates via dischargevalve 121 with the atmosphere or a return duct 122, the latter leadingto the heating plant. In a manner similar to that shown in FIG. 4, thefoundation also includes an air-supply duct 123 through which thepressurizing and ventilating air is delivered.

In the detail view of FIG. 13, a valve structure is shown in somewhatgreater detail. In FIG. 11, however, the system has been illustratedwith the valve 118 in an open condition and valve 119 closed. When valve119 is closed, air is prevented from circulating through the interwallcompartment and is, instead, released directly into the atmosphere. Inthis case, the inner covering layer is no longer supported by air withinthe interwall space and collapses against the outer covering layer 101.Opening of valve 119 permits air to flow into the wall space and,consequently, spreads the covering layers 101 and 102 apart. The valvemember 118 may have an oval cross section (FIG. 13) to block the ventopening. The edge of the outer covering layer 101 extends beneath thevalve member 118 and grips the latter. A pressure drop within thechamber will cause atmospheric pressure on the left-hand side of thevalve member 118 to shift to the right and cause it to fall into thetrough 124 formed as an extension upon the inner wall covering layer102. The space 126 ensures release of the valve by suction andre-engagement under pressure. Projections 127 may be provided to permitthe flow cross section to be established with considerable accuracy andto allow draining of condensate, and proper choice of the materials forthe valve housing and the ball valve block 118 will suffice to permitany degree of blockage and control that may be necessary. The memberserves as a collecting shield for condensate developing along the innersurface of dome 117 and delivers such condensate to the trough 124 fromwhich it may flow through the channel between the covering layers to thefoundation.

In FIG. 14, I have shown a system for joining a pair of inner fabricstrips 129 and 102 together and to an outer covering 1. The devicecomprises a bead-forming element thermally bonded or vulcanized to theouter covering layer 1 along the entire seam. Between the bead 128 andthe strips 102, 129, I dispose an intermediate profile member whichlikewise extends the entire length of the seam and is provided with alongitu dinally extending groove in which the bead 128 is received. Apair of grooves 130a and 130b receives the beads 129 of the innercovering layers to be joined along the strip. A further groove 130sreceives the bead of a cover strip 31 which masks the junction FIGS. 15and 16 are directed to yet another feature of the invention in which arigid window element 33 is formed with a base plate 34 provided withair-discharge openings 35. The base plate 34 extends beneath therearwardly bent upper portion of the frame and the center of gravity ofthe entire structure preferably lies within the outline of this baseplate or within the latter proper. The external periphery of the frameis formed with a channel in which the flexible covering 101 can be heldby a tension wire 109. Sealing may be provided by a profile 36 of somesuitable material such as rubber which is fitted into the annulargroove. The frame is also provided with an internal groove in which thewindow elements, preferably an outer shell 108 and an inner shell 107 ofplexiglass, can be fixed. The arch shape of the window frame 33, whichcorresponds to a doubly-curved surface in effect, pennits the tensionwire 109 to press against the frame uniformly at all locations.Tensioning screws 37 lock the wire 109 in place and hence also fix thecovering to the window structure. The base plate 34 engages laterallyagainst the frame element to resist the inward pressure applied by thebottom-span wire 109. The window element is preferably cast from asynthetic resin or concrete in an elastic form 38 of a fiber-glassreinforced polyester resin which is positioned by angle members 39mounted upon a wooden support structure 40. Securing the mold to thesupport structure and positioning the mold is the function of the screws42'. The necessary grooves or ridges of the form may be provided byappropriately dimensioned parts 38 which are assembled to define thecasting cavity.

In FIG. 18, I show a cross section of the bottom or base connection ofthe pneumatically supported structure. The outer covering layer 101 isprovided along its lower rim with a loop in which a stiffening profile42 extends. The approximately round cross section of this profile isclamped from the exterior of the covering 101 and by screws 44 and nuts45 fastened to the foundation 34a. By twisting or tilting the profileabout its longitudinal axis, the loop of the covering 101 is stretchedbetween the round portion of the profile to the tilted profile portion.The stretched loop portion is pressed against a ridge 46 of thefoundation element to provide an absolutely leakproof seal between thefoundation and the covering. Thin-wall elements 47 are set upon thefoundation 34a and carry the inner covering layer 102 to provide a tightconnection between the inner covering layer and the foundation. Slots 48are provided in the foundation to communicate with the interwallcompartments and conduct the discharged air into the return duct.

FIG. 19 shows a spacer of insulating elastic material of light weight,such as foam, synthetic resin or an elastomer. This spacer has a centralportion with an elongated nose 49 turned toward the inner edge and ashort nose 50 which carries a shell 51. The latter, with its edge lyingagainst the outer edge, also defines an insulating air space 52. Thisspacer is placed upon a naillike pin 53 fastened to the outer wall. Theinner shell is connected to the same pin. Equalization openings are alsoprovided in shell 51.

The improvement described and illustrated is believed to admit of manymodifications within the ability of persons skilled in the art, all suchmodifications being considered within the spirit and scope of theinvention except as limited by the appended claims.

I claim:

1. A pneumatically-supported structure, comprising a polyhedralfoundation having a plurality of spaced apart anchor joints with pairsthereof defining sides of the structure; elongated anchor elemnttsspanning diagonally opposite anchor points under tension and secured tosaid foundation said anchor elements meeting at a diagonal intersection;and a flexible gas-retentive covering enclosing the space within saidfoundation and retained against outward force by said elements uponinternal pneumatic pressurization of the enclosure, said covering beingformed by flexible segments each spanning the space between two suchanchor elemnts, adjacent segments being seamed along said anchorelements and said anchor elements being received within said covering;and means for maintaining an air pressure along an internal surface ofsaid covering greater than atmospheric pressure.

2. The pneumatically-supported structure defined in claim 1, furthercomprising a plurality of genreally vertical posts spaced apart along atleast one of said sides and spanned by said cover.

3. The pneumatically-supported structure defined in claim 1, furthercomprising at least one rigid arch spanning anchor points along at leastone of said sides and sealingly connected to said cover.

4. The pneumatically-supported structure defined in claim 3, furthercomprising a plurality of vertically extending posts spaced horizontallyapart along said one of said sides and reaching from the ground to saidarch for supporting same.

5. The pneumatically-supported structure defined in claim 3 wherein saidarch lies generally in a plane inclined outwardly from said enclosure,said structure further comprising a plurality of vertically extendingtension elements reaching from the ground to said arch.

6. The pneumatically-supported structure defined in claim 3 wherein aplurality of such arches are provided along respective sides of thestructure, said arches and said covering being so constructed andarranged that said covering is supported by said arches above gradelevel upon depressurization of said enclosure.

7. The pneumatically-supported structure defined in claim 1,. furthercomprising an interior framework within said enclosure for supportingsaid covering upon depressurization of said enclosure.

8. The pneumatically-supported structure defined in claim 1, furthercomprising an elongated supporting mast within" said enclosure andmovably acting upon said anchor elements for maintaining at least partsof the length thereof under tension while enabling a portion of saidenclosure to be opened to the atmosphere.

9. The pneumatically-supported structure defined in claim 1 wherein saidcovering is formed with a plurality of discrete air-flow compartments,further comprising means for inducing a flow of air from the interior ofsaid enclosure through said compartments, and duct means for collectingthe air traversing said compartments.

10. The pneumatically-supported structure defined in claim 9, furthercomprising valve means in an upper portion of said enclosure forselectively connecting the interior of said enclosure to saidcompartments and to said atmosphere.

11. The pneumatically-supported structure defined in claim 10 whereinsaid duct means forms part of said foundation, said foundation furthercomprising airsupply means for delivering air to said enclosure.

12. The pneumatically-supported structure defined in claim 1, furthercomprising a window element receivable in said enclosure and comprisinga base plate, and a frame member rising from said base plate and curvedto conform to the configuration of said enclosure, said frame memberbeing spanned by at least one shell, the central gravity of said windowelement lying within the outline of said base plate.

13. The pneumatically-supported structure defined in claim 1 whereinsaid anchor elements each comprise a pair of parallel wires and meansfor holding the wires of each pair together.

14. The pneumatically-supported structure defined in claim 1 whereinsaid anchor elements each comprise a plurality of bands and means forholding the bands of each element together.

15. A pneumatically supported structure comprising a foundation, aflexible covering overlying said foundation, means for maintaining apressure along an inner surface of said covering in excess ofatmospheric pressure to pneumatically support said covering, saidcovering being of double-wall construction and forming passages betweenwalls thereof, said passages running downwardly from locations close tothe top of said structure to locations close to the bottom thereof, andmeans for circulating air through said structure and said passageswhereby air enters said passages at said locations close to the top ofsaid structure and emerges from said passages close to the bottomthereof, said structure being further provided with openings around saidfoundation for admitting fresh air to the entrance of said structure.

16. A pneumatically-supported structure, comprising a foundation havinga plurality of spaced apart anchor points with pairs thereof definingsides of the structure; elongated anchor elements spanning diagonallyopposite anchor points and secured to said foundation; a flexiblegas-retentive covering enclosing the space within said foundation andretained against outward force by said elements upon internal pneumaticpressurization of the enclosure; and at least one rigid arch spanninganchor points along at least one of said sides and sealingly connectedto said cover; said arch being provided with a sealing edge formed withlongitudinally extending corrugations, a sealing strip overlying saidedge, and means for maintaining one edge of said covering in sealingengagement with said strip.

17. A pneumatically-supported structure, comprising a foundation havinga plurality of spaced apart anchor points with pairs thereof definingsides of the structure; elongated anchor elements spanning diagonallyopposite anchor points and secured to said foundation; a flexiblegas-retentive covering enclosing the space within said foundation andretained against outward force by said elements upon internal pneumaticpressurization of the enclosure; a window element receivable in saidenclosure and comprising a base plate, and a frame member rising fromsaid base plate and curved to conform to the configuration of saidenclosure, said frame member being spanned by at least one shell, thecenter of gravity of said window element lying within the outline ofsaid base plate; and a tension wire extending around said frame memberfor anchoring same to said covering, and a further wire spanning saidframe member at the lower end thereof for retaining said frame memberagainst said base plate.

11. The pneumatically-supported structure definein claim 10 wherein saidduct means forms part of said foundtaion, said foundation furthercomprising airsupply means for delivering air to said enclosure.

* t l v W105" UNITED STATES PATENT OFFECE QERTEFECATE 0F CQRRECTIONPotent No. 3q'75lA862i V I Dated 14 Aug U31. 197,3

Inventor-(s) Josef LINECKER It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

In the heading, between lines "[21]" and "[52]", the folbowing insert bemade 7 v "K301 PoREIGN'APPLicATIoN PRIORITY BATA 2 Am-n 1970 Austria3027/70 2'1 August'1970 Austria'7791/70 signed and sealed this 12th dayof March 1974.

(SEAL) Attest: v

EDWARD MQFLETCHERQJR. I e c. MARSHALL DANN Attestipg Officer-- A I ACommissioner of Patents

1. A pneumatically-supported structure, comprising a polyhedralfoundation having a plurality of spaced apart anchor joints with pairsthereof defining sides of the structure; elongated anchor elemnttsspanning diagonally opposite anchor points under tension and secured tosaid foundation said anchor elements meeting at a diagonal intersection;and a flexible gas-retentive covering enclosing the space within saidfoundation and retained against outward force by said elements uponinternal pneumatic pressurization of the enclosure, said covering beingformed by flexible segments each spanning the space between two suchanchor elemnts, adjacent segments being seamed along said anchorelements and said anchor elements being received within said covering;and means for maintaining an air pressure along an internal surface ofsaid covering greater than atmospheric pressure.
 2. Thepneumatically-supported structure defined in claim 1, further comprisinga plurality of genreally vertical posts spaced apart along at least oneof said sides and spanned by said cover.
 3. The pneumatically-supportedstructure defined in claim 1, further comprising at least one rigid archspanning anchor points along at least one of said sides and sealinglyconnected to said cover.
 4. The pneumatically-supported structuredefined in claim 3, further comprising a plurality of verticallyextending posts spaced horizontally apart along said one of said sidesand reaching from the ground to said arch for supporting same.
 5. Thepneumatically-supported structure defined in claim 3 wherein said archlies generally in a plane inclined outwardly from said enclosure, saidstructure further comprising a plurality of vertically extending tensionelements reaching from the ground to said arch.
 6. Thepneumatically-supported structure defined in claim 3 wherein a pluralityof such arches are provided along respective sides of the structure,said arches and said covering being so constructed and arranged thatsaid covering is supported by said arches above grade level upondepressurization of said enclosure.
 7. The pneumatically-supportedstructure defined in claim 1, further comprising an interior frameworkwithin said enclosure for supporting said covering upon depressurizationof said enclosure.
 8. The pneumatically-supported structure defined inclaim 1, further comprising an elongated supporting mast within saidenclosure and movably acting upon said anchor elements for maintainingat least parts of the length thereof under tension while enabling aportion of said enclosure to be opened to the atmosphere.
 9. Thepneumatically-supported structure defined in claim 1 wherein saidcoveRing is formed with a plurality of discrete air-flow compartments,further comprising means for inducing a flow of air from the interior ofsaid enclosure through said compartments, and duct means for collectingthe air traversing said compartments.
 10. The pneumatically-supportedstructure defined in claim 9, further comprising valve means in an upperportion of said enclosure for selectively connecting the interior ofsaid enclosure to said compartments and to said atmosphere.
 11. Thepneumatically-supported structure defined in claim 10 wherein said ductmeans forms part of said foundation, said foundation further comprisingair-supply means for delivering air to said enclosure.
 11. Thepneumatically-supported structure definein claim 10 wherein said ductmeans forms part of said foundtaion, said foundation further comprisingair-supply means for delivering air to said enclosure.
 12. Thepneumatically-supported structure defined in claim 1, further comprisinga window element receivable in said enclosure and comprising a baseplate, and a frame member rising from said base plate and curved toconform to the configuration of said enclosure, said frame member beingspanned by at least one shell, the central gravity of said windowelement lying within the outline of said base plate.
 13. Thepneumatically-supported structure defined in claim 1 wherein said anchorelements each comprise a pair of parallel wires and means for holdingthe wires of each pair together.
 14. The pneumatically-supportedstructure defined in claim 1 wherein said anchor elements each comprisea plurality of bands and means for holding the bands of each elementtogether.
 15. A pneumatically supported structure comprising afoundation, a flexible covering overlying said foundation, means formaintaining a pressure along an inner surface of said covering in excessof atmospheric pressure to pneumatically support said covering, saidcovering being of double-wall construction and forming passages betweenwalls thereof, said passages running downwardly from locations close tothe top of said structure to locations close to the bottom thereof, andmeans for circulating air through said structure and said passageswhereby air enters said passages at said locations close to the top ofsaid structure and emerges from said passages close to the bottomthereof, said structure being further provided with openings around saidfoundation for admitting fresh air to the entrance of said structure.16. A pneumatically-supported structure, comprising a foundation havinga plurality of spaced apart anchor points with pairs thereof definingsides of the structure; elongated anchor elements spanning diagonallyopposite anchor points and secured to said foundation; a flexiblegas-retentive covering enclosing the space within said foundation andretained against outward force by said elements upon internal pneumaticpressurization of the enclosure; and at least one rigid arch spanninganchor points along at least one of said sides and sealingly connectedto said cover; said arch being provided with a sealing edge formed withlongitudinally extending corrugations, a sealing strip overlying saidedge, and means for maintaining one edge of said covering in sealingengagement with said strip.
 17. A pneumatically-supported structure,comprising a foundation having a plurality of spaced apart anchor pointswith pairs thereof defining sides of the structure; elongated anchorelements spanning diagonally opposite anchor points and secured to saidfoundation; a flexible gas-retentive covering enclosing the space withinsaid foundation and retained against outward force by said elements uponinternal pneumatic pressurization of the enclosure; a window elementreceivable in said enclosure and comprising a base plate, and a framemember rising from said base plate and curved to conform to theconfiguration of said enclosure, said frame member being spanned by atleast one shell, the center of gravity of said window element lyingwithin the outline of said base plate; and a tension wire extendingaround said frame member for anchoring same to said covering, and afurther wire spanning said frame member at the lower End thereof forretaining said frame member against said base plate.